1. Field of the Invention
The invention relates to novel compositions in powder form and to their use as a texturizer in cosmetic, dermopharmaceutical and pharmaceutical applications and in the treatment of paper or textiles.
2. Related Art
Texturizers are frequently used in producing formulations intended for caring for or making up the skin or mucosae or else in application to substrates such as paper or textiles. Their principal function is to enhance the sensorial and Theological properties of the formulations in which they are incorporated or of the substrates to which they are applied. Examples of texturizers used in cosmetology include polymethyl methacrylate powders (Micropearl™), polyamide powders (Nylon™), silicone powders (DC9506™, Polytrap™), and modified starches (Dry Flo™). Some of these powders produce in the user a sensation of softness on spreading and a lasting powdery feel; others inhibit the greasy sensation felt on spreading and bring about a long-lasting matting effect.
Some amino acid derivatives, such as N-lauroyl-lysine, are sometimes added to makeup formulas in order to combine the effects of softness on application and staying power on the skin. This effect may also be obtained by treating the surface of the powders with various compounds, including amino acids.
In certain cases fibres are also added to the formulations, either natural fibres such as cellulose or cotton fibres or synthetic fibres such as polyethylene, Teflon or polyester fibres, in order to modify the Theological characteristics of the formulas or to enhance both the uniformity of their distribution on the surface to be coated and their staying power thereon.
Certain fillers, such as talc, mica, sericite or else composite fillers, are also used in order to modify the lubricating properties of the formulation and to facilitate flow or spreading on the substrate.
Other types of pigmentary fillers, such as titanium oxide, zinc oxide or iron oxides, may also be incorporated into these formulations in order to modify their transparency or colour on application while influencing their final texture.
These powders are, generally speaking, well suited to the manufacture of loose powder or compact powder formulations or of formulations with a continuous fatty phase, such as water-in-oil emulsions, water-in-silicone-oil emulsions, sticks and other compact formulas.
In contrast, they are often difficult to employ in media having a continuous aqueous phase, such as lotions, gels, cream gels or oil-in-water emulsions. In such cases it is necessary to carry out specific and expensive preliminary studies, for each powder and each type of formulation, in order to obtain both effective dispersion of the powder and satisfactory stability of the formulation.
The formulator is then often compelled to use either hydrophilic microporous microspheres of Micropearl™ type, in combination with stabilizers, or powders which have been surface-treated to enhance compatibility with the other ingredients of the formulation. In this latter case, however, the appropriate treatment is specific to the formulation selected and, moreover, does not relieve the formulator of the task of a stability study on the treated powder selected within the formulation. Finally, this last solution is not generally suitable for formulations of the type with a continuous aqueous phase, either in the absence or in the presence of a small proportion of fatty phase.
Consequently, in the context of its research into improving the texture of formulations, the applicant has sought to develop new texturizers in powder form which are multi-functional and are easy to employ, both in solid formulations of loose powder or compact powder type and in formulations with a continuous fatty phase or in formulations with a continuous aqueous phase, with or without a small proportion of fatty phase.